/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
    * with the License.  You may obtain a copy of the License at
    *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  package org.apache.maven.repository.internal;
  
  import java.util.Map;
  import java.util.Objects;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.function.Supplier;
  
  import org.apache.maven.building.Source;
  import org.apache.maven.model.building.ModelCache;
  import org.eclipse.aether.RepositorySystemSession;
  
  /**
   * A model builder cache backed by the repository system cache.
   *
   */
  public class DefaultModelCache implements ModelCache {
  
      private static final String KEY = DefaultModelCache.class.getName();
  
      private final Map<Object, Supplier<?>> cache;
  
      public static ModelCache newInstance(RepositorySystemSession session) {
          Map<Object, Supplier<?>> cache;
          if (session.getCache() == null) {
              cache = new ConcurrentHashMap<>();
          } else {
              cache = (Map) session.getCache().get(session, KEY);
              if (cache == null) {
                  cache = new ConcurrentHashMap<>();
                  session.getCache().put(session, KEY, cache);
              }
          }
          return new DefaultModelCache(cache);
      }
  
      private DefaultModelCache(Map<Object, Supplier<?>> cache) {
          this.cache = cache;
      }
  
      public Object get(Source path, String tag) {
          return get(new SourceCacheKey(path, tag));
      }
  
      public void put(Source path, String tag, Object data) {
          put(new SourceCacheKey(path, tag), data);
      }
  
      @Override
      public Object get(String groupId, String artifactId, String version, String tag) {
          return get(new GavCacheKey(groupId, artifactId, version, tag));
      }
  
      @Override
      public void put(String groupId, String artifactId, String version, String tag, Object data) {
          put(new GavCacheKey(groupId, artifactId, version, tag), data);
      }
  
      protected Object get(Object key) {
          Supplier<?> s = cache.get(key);
          return s != null ? s.get() : null;
      }
  
      protected void put(Object key, Object data) {
          cache.put(key, () -> data);
      }
  
      @Override
      public Object computeIfAbsent(
              String groupId, String artifactId, String version, String tag, Supplier<Supplier<?>> data) {
          return computeIfAbsent(new GavCacheKey(groupId, artifactId, version, tag), data);
      }
  
      @Override
      public Object computeIfAbsent(Source path, String tag, Supplier<Supplier<?>> data) {
          return computeIfAbsent(new SourceCacheKey(path, tag), data);
      }
  
      protected Object computeIfAbsent(Object key, Supplier<Supplier<?>> data) {
          Supplier<?> s = cache.computeIfAbsent(key, k -> data.get());
          return s != null ? s.get() : null;
      }
 
     static class GavCacheKey {
 
         private final String gav;
 
         private final String tag;
 
         private final int hash;
 
         GavCacheKey(String groupId, String artifactId, String version, String tag) {
             this(gav(groupId, artifactId, version), tag);
         }
 
         GavCacheKey(String gav, String tag) {
             this.gav = gav;
             this.tag = tag;
             this.hash = Objects.hash(gav, tag);
         }
 
         private static String gav(String groupId, String artifactId, String version) {
             StringBuilder sb = new StringBuilder();
             if (groupId != null) {
                 sb.append(groupId);
             }
             sb.append(":");
             if (artifactId != null) {
                 sb.append(artifactId);
             }
             sb.append(":");
             if (version != null) {
                 sb.append(version);
             }
             return sb.toString();
         }
 
         @Override
         public boolean equals(Object obj) {
             if (this == obj) {
                 return true;
             }
             if (null == obj || !getClass().equals(obj.getClass())) {
                 return false;
             }
             GavCacheKey that = (GavCacheKey) obj;
             return Objects.equals(this.gav, that.gav) && Objects.equals(this.tag, that.tag);
         }
 
         @Override
         public int hashCode() {
             return hash;
         }
 
         @Override
         public String toString() {
             return "GavCacheKey{" + "gav='" + gav + '\'' + ", tag='" + tag + '\'' + '}';
         }
     }
 
     private static final class SourceCacheKey {
         private final Source source;
 
         private final String tag;
 
         private final int hash;
 
         SourceCacheKey(Source source, String tag) {
             this.source = source;
             this.tag = tag;
             this.hash = Objects.hash(source, tag);
         }
 
         @Override
         public String toString() {
             return "SourceCacheKey{" + "source=" + source + ", tag='" + tag + '\'' + '}';
         }
 
         @Override
         public boolean equals(Object obj) {
             if (this == obj) {
                 return true;
             }
             if (null == obj || !getClass().equals(obj.getClass())) {
                 return false;
             }
             SourceCacheKey that = (SourceCacheKey) obj;
             return Objects.equals(this.source, that.source) && Objects.equals(this.tag, that.tag);
         }
 
         @Override
         public int hashCode() {
             return hash;
         }
     }
 }